Miscarriage

In this episode of PodMD, Australian-trained gynaecologist Dr Alison Bryant-Smith will be discussing miscarriage, including what miscarriage is, the different sub-types of miscarriage, how common it is amongst women, how it is investigated, when a GP should refer and more.


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  • Transcript
    Please note this is a machine generated transcription and may contain some errors.
    *As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.

    Today I’d like to welcome to the PodMD studio Dr Alison Bryant-Smith

    Alison is an Australian-trained gynaecologist, with expertise in advanced laparoscopic surgery. Melbourne born and bred, she completed medical school at The University of Melbourne, then obstetrics and gynaecology training through The Royal Women’s Hospital, including several years working in London at Guy’s and St Thomas. It was here that her interest in keyhole surgery was piqued. She then moved to Sydney, and completed a two year laparoscopic surgery Fellowship with esteemed A/Prof Alan Lam.

    Since moving back to Melbourne, she has juggled three public appointments, while being integral in establishing Maven (pronounced ‘May-ven’) Centre: multidisciplinary consulting suites within Sunshine Private Hospital.

    *We do hope you enjoy this podcast but please remember that the advice here is of a general nature and is not intended as specific advice about a given patient. The views and opinions expressed in this podcast are those of the doctor, not PodMD.
    If you do have a patient on whom you require specific advice, then please seek advice from a colleague with appropriate expertise in that area.

    Alison, thanks for talking with us on PodMD today.

    Alison : Thank you for having me. To start, I’d like to acknowledge that we’re recording this podcast on the lands of the Wurundjeri people, and I’d like to acknowledge them as Traditional Owners. I’d also like to pay my respects to their Elders, past present and emerging. I’d also like to acknowledge that in today’s podcast, for brevity’s sake, I’ll use the word ‘woman’, and pronouns ‘she and her’ to refer to any patient who was assigned female at birth.

    Question 1
    The topic of today’s discussion is miscarriage.Alison, can you describe for our listeners what miscarriage is?

    Alison: The terminology surrounding miscarriage is quite confusing, but hopefully I can help to clear it up a little. Miscarriage is the unintentional loss of an intra-uterine pregnancy, up to 20 weeks’ gestation. After 20 weeks, the term ‘fetal death in utero’ is used.
    ‘Miscarriage’ should be not used interchangeably with either ‘abortion’ or ‘failed pregnancy’. ‘Abortion’ is the intentional interruption of a viable ongoing pregnancy, and is quite an emotionally-laden term that has been superceded by the phrase ‘termination of pregnancy’. ‘Failed pregnancy’ can be seen to be blaming the patient, and adding to the feelings of misplaced guilt that many women experience after a miscarriage.
    There are seven different sub-types of miscarriage, which just adds to the confusing terminology. These include:
    – Missed miscarriage (spelt M I S S E D)
    – Threatened miscarriage
    – Inevitable miscarriage
    – Incomplete miscarriage
    – Complete miscarriage
    – Recurrent miscarriage
    – Septic miscarriage

    I’m happy to talk through these different sub-types later in this podcast episode.

    Question 2
    How common is miscarriage?

    Alison: Sadly, miscarriages are very common. It’s estimated that approximately 15%, or 1 in 6, recognised pregnancies end in miscarriage. By ‘recognised pregnancies’, I mean that the patient has had at least a positive urinary BhCG.

    The actual rate is probably much higher (even up to 2 in 3 pregnancies), as many women may miscarry before they even realise they were pregnant: what was thought to be a ‘late and heavy period’ may actually have been an early miscarriage.

    The vast majority of miscarriages occur in the first 12 weeks of pregnancy. And most of these embryos are found to chromosomally abnormal. The way I explain it to patients is that their genes and their partner’s didn’t line up correctly, and this was nature’s way of saying that this was never going to be a happy and healthy baby. I’m hoping explaining their miscarriage like this helps to assuage any misplaced guilt they may be feeling.
    Risk factors that increase a woman’s likelihood of miscarrying include:Increasing maternal age, particularly after the age of 35yo. The baseline risk of miscarriage is 15%, by 35yo that jumps to 25%, and up to 50% by age 40. This association (between increasing maternal age and increasing risk of miscarriage) is confounded by the increasing risk of as women age, as trisomic pregnancies often result in miscarriage.

    Another risk factor for miscarriage is previous miscarriage. Having had a miscarriage previously is a risk factor for future miscarriage, independent of maternal age. This risk really increases exponentially once you’ve had three miscarriages, when your risk of having another miscarriage in your next pregnancy is approximately 60%

    Question 3
    How would a patient with a miscarriage typically present?

    Alison: Different types of miscarriages present in different ways. So it might help here to talk through the natural history of a miscarriage, if you will.

    A common scenario is that a woman presents for her first trimester dating scan, at approximately 6 – 8 weeks’ gestation. She is asymptomatic – hasn’t had any pelvic cramps or vaginal bleeding. Unfortunately a fetal heart rate can’t be seen, even though it should be at that gestation. This is called a ‘missed miscarriage’: when the embryo stops growing, and the patient is asymptomatic.

    In contrast, a so-called ‘threatened miscarriage’ is one in which the woman has vaginal bleeding. She may or may not have pelvic cramps. By definition, any vaginal bleeding in the first half of pregnancy is called a ‘threatened miscarriage’ until proven otherwise. This occurs in approximately 1 in 5 pregnancies. In over 90% of such cases, the fetal heart rate is seen on ultrasound, and the pregnancy continues on.

    The phrase ‘inevitable miscarriage’ refers to the combination of vaginal bleeding, pelvic cramps, and cervical dilatation in the first half of pregnancy. As the name implies, there is little that can be done to prevent the ensuring miscarriage from occurring.

    Now we move on to a so-called ‘incomplete miscarriage’, in which some of the products of conception have been expelled through the cervix, but some remain in situ in the uterus. (Products of conception is an umbrella term for placental and embryonic tissue.) The patient would have experienced significant vaginal bleeding and pelvic cramps when the initial products of conception were being expelled. On ultrasound, there will not be any evidence of fetal viability. Incomplete miscarriages tend to occur later in pregnancy (eg. between 12 – 20 weeks’ gestation). Commonly, the fetus may be expelled, then the umbilical cord breaks, and the placenta is left inside.

    In contrast to an incomplete miscarriage, in a ‘complete miscarriage’, the woman’s body naturally expels the entirety of the products of conception (placental and embryonic tissue). She would have experienced significant pain and bleeding during the miscarriage, which then settles over the coming hours.

    So I’ve now outlined the natural history of a miscarriage: from missed (prior to the development of symptoms), to inevitable (once bleeding and pain develop, and the cervix starts to open), incomplete (when some placental and / or embryonic tissue has passed, but some remains in situ), to complete (when all the products of conception have passed spontaneously).

    Septic miscarriages are (thankfully) quite rare, and refer to an incomplete miscarriage that is complicated by retained products of conception and severe intra-uterine infection. Patients may give a history consistent with a recent incomplete miscarriage. Classic symptoms thereafter are pelvic and abdominal pain, purulent vaginal discharge and fever. Without timely surgical evacuation and broad-spectrum antibiotics, these patients can deteriorate surprisingly quickly, developing sepsis, and life-threatening multi-organ failure.

    A quick note about so-called ‘recurrent miscarriage’, which is when a woman has had three miscarriages in a row. Thankfully, this is quite rare, and warrants referral to your local hospital’s recurrent miscarriage or gynaecology clinic for investigation and management.

    Question 4
    How are miscarriages investigated?

    Alison: Most patients have already done a urine pregnancy test themselves, and present knowing that they are pregnant. If not, it’s worth doing one.
    Once a woman has had a positive urine pregnancy test, it’s helpful to request a BhCG blood test, and a blood group (to ascertain her Rhesus status). Knowing a patient’s blood group is helpful. If the patient is beyond 11 weeks’ gestation, or if medical or surgical management is needed, and the patient is Rhesus negative, we’ll need to give her an anti-D injection to prevent iso-immunisation in later pregnancies.
    Then a transvaginal ultrasound should be requested. Transvaginal ultrasound is the key investigation when it comes to miscarriage, as this will be able to determine what’s going on. A good quality ultrasound will be able to tell you:
    – If the embryo can be visualised, or if it’s too early (ie. the embryo is too small to see), in which case a repeat ultrasound is warranted 1 – 2 weeks later
    – The location of the pregnancy: is it intra-uterine or ectopic ?
    – The viability of the pregnancy: is this a viable, ongoing pregnancy, or has the embryo has stopped growing (ie. a miscarriage occurred)

    Question 5
    What are the treatment options?

    ALison: Broadly speaking, the management of miscarriage can be broken down into supportive, expectant, medical, or surgical management.
    Supportive management includes:
    – Using an empathetic, patient-centred approach
    – Providing psychological support to both the patient, and her partner (if relevant)
    – Reassuring her that the miscarriage was not her fault, and that there was nothing she could do to change the outcome
    – Expectant management is appropriate for incomplete miscarriages (if the patient is willing to await the spontaneous completion of their miscarriage), or in a complete miscarriage (when her body has already expelled all of the placental and embryonic tissue). Your local hospital will have an ‘early pregnancy assessment service’, that patients can be referred to for appropriate follow-up investigations (if needed).

    Medical management involves the administration of vaginal misoprostol. Misoprostol is a prostaglandin analogue, that encourages the expulsion of any remaining placental and / or embryonic tissue. Patients are admitted to hospital for a few hours of observation and pain relief during this process, then followed up appropriately through the hospital’s early pregnancy service. Medical management is appropriate for incomplete miscarriages, to encourage the expulsion of the remaining products of conception.

    Surgical management involves a so-called ‘suction dilatation and curettage’, which is a day procedure performed under general anaesthetic. Once the patient is asleep, narrow suction tubing is inserted through the vagina and cervix into the uterine cavity, and any remaining placental or embryonic tissue is extracted using this suction device. Patients who have had a missed miscarriage, or are haemodynamically unstable due to heavy vaginal bleeding are often advised to have a suction D&C.

    Question 6
    How can GPs improve the management of miscarriage?

    Alison: Any woman who is considering pregnancy should be advised to optimise their health prior, to decrease their risk of miscarriage. In particular:
    – Optimise medical comorbidities such as diabetes or obesity
    – Minimise the use of alcohol, smoking and illicit drugs
    – Normalise thyroid function

    Consideration could be given to commencing low dose aspirin and progesterone supplementation in women who are at high risk of miscarriage, although the evidence base here is quite mixed.

    If a pregnant woman has vaginal bleeding during early pregnancy, a transvaginal ultrasound is a great first investigation. Then referral on to your local hospital’s early pregnancy assessment service for further management.

    Question 7
    What is the likelihood of recurrence of miscarriage?

    Alison: The population-wide, baseline risk of miscarriage in a first pregnancy is approximately 15%. This increases ever so slightly with subsequent pregnancies, to 23%, then 33%. So if you’ve had two miscarriages previously, there is a 33% chance of having another miscarriage.
    This jumps up dramatically after three miscarriages, to a 60% chance of having a fourth miscarriage. This is partly why women who have had three consecutive miscarriages (which is called ‘recurrent miscarriage’) warrant referral to your local gynaecology clinic. By a woman’s third miscarriage, it’s worth thoroughly investigating whether there are underlying factors contributing to her repeated miscarriages.

    Question 8
    Have there been any developments in the management of miscarriage in the last few years?

    Alison: Over the last few years, there has been increasing interest in the use of progesterone supplementation early in pregnancy, to decrease the risk of later miscarriage. As it stands at the moment, there is no consensus among the various international Colleges of Obstetrics and Gynaecology. The Australian College of Obstetricians and Gynaecologists says that progesterone ‘can be considered’ in women who present with threatened miscarriage, in an attempt to reduce the likelihood of that bleeding progressing to a fetal loss. This is in keeping with guidance from the UK College. The American College only advises progesterone for women who have had three miscarriages previously.

    Similarly, there is no consensus regarding the use of low dose aspirin (commenced prior to conception) to decrease the risk of later miscarriage.

    Concluding Question
    Thank you for your time here today in the PodMD studio. To sum up for us, could you please identify the three key take home messages from today’s podcast on miscarriage.

    Alison: 1. Miscarriage is, unfortunately, quite common. More often than not, a miscarriage is due to an underlying chromosomal abnormality of the developing embryo, and should not be attributed to any actions by the mother.

    2. The jury is out regarding the evidence base for progesterone and low dose aspirin in preventing miscarriage. For women who have previously had a miscarriage, some clinicians reason that there is little (if any) potential harm in recommending progesterone and low dose aspirin from prior to conception through to the end of the first trimester of pregnancy.

    3. Management of miscarriage can be broken down into supportive, expectant, medical and surgical. When in doubt, request a transvaginal ultrasound, then refer the patient to your local hospital’s early pregnancy assessment service.

    Thanks for your time and the insights you’ve provided.

    Alison: Thank you

*As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.